Question about Outlook Express

My isp is TWC Road Runner. My emails come into their server.  I can transfer the emails to Outlook Express with no problem and the emails are now located in both the server and my Outlook Express inbox.  I recently purchased a smart phone from Tracfone an LG 840G. I set up the incoming and outgoing info with port #'s and file names that I received from TWC.  I can now access the emails that are located in the server from my cell phone.  I can now see all the emails on my cell phone inbox that are sitting in the server inbox.  The problem I have is that when I open a given email that is in the inbox on my cell phone, it gets deleted from the server which then prevents me from transferring it from the server to Outlook at a later date on my computer.  I have gone round and round with both Tracfone and TWC with no resolution.  Help!!!

John Moretti